Color Mixing

In watercolor, there are two basic approaches to mixing color- either by combining two or more pigments on your palette or by laying one color on top of another on the paper. In the first method- what we call physical mixing, we might mix cadmium red with cadium yellow to create an orange hue. In the second method- what we might call optical mixing or glazing, we would paint a light red wash, wait for it to dry and then apply a yellow wash. Try both methods- since each one has useful applications.

physical mixing- colors mixed on the palette, or on paper simultaneously to create desired color.

optical mix or glazing*- colors are mixed in successive transparent layers, with drying time in between. The color on top affects the colors on the bottom. This creates the effect of mixed color as in colored cellophane.
*See this link for a more in-depth explanation of optical mixing/glazing.